Windows build failures

[Geert Janssens]

I have noticed the windows builds are failing with this error:
cc1.exe: warnings being treated as errors
../../../repos/src/gnome-utils/gnc-tree-view.c: In function 
'gnc_tree_view_get_column_order':
../../../repos/src/gnome-utils/gnc-tree-view.c:851:5: error: format 
'%lu' expects type 'long unsigned int', but argument 5 has type 'gsize'
make[5]: *** [gnc-tree-view.lo] Error 1

I have written that code. On linux (at least Fedora 19, 64-bit) gsize is 
defined as unsigned long. It looks like that is not the case on a 32-bit 
windows XP system.

It's too late here now to look at it. But if no one beats me to it, I'll 
try and fix it tomorrow.

Geert